Telescopic sight.



W. v. HUKILL.

TBLESGOPIG SIGHT. APPLICATION FILED uns. 1913.

L Patented Jn.2o,1914

MM L Amzwfrs narran STATE-sf? WILLIAM V. HUKILL, 0F BETHANY, WEST VIRGINIA.

TELESCOPIC SIGHT.

Specification of Letters Patent.

'Patented .13.11.20, 1914.

Application filed May 8, 1913. Serial No. 766,282.

To all whom it may oncem Beit known that I, WILLIAM V. HUKILL, a citizen of the United States, and a resident of Bethany, `in 4the county of Brooke and State of 'West Virginia, have invented a new and Improved Telescopic Sight, of which the following is a full, clear, and exact description. l

The invention relates to Galilean telescopes and its vobject is to provide a new and improved sight for such telescopes to permit the use of the Galilean telescope on surveying instruments, rifles and other devices for sighting purposes.

In order to accomplish the desired result use is made of cross Wires and a diaphragm, of which the cross Wires are associated With the concave eye-piece of the telescope and 'the diaphragm is associated with the objective of the telescope, and the said diaphragm is provided with an opening and with slots whereby a field is obtained having a bright portion due to the opening and dimmed portions due to the slots and in which the side portions of the cross .Wires are visible when using the telescope while the central portion of the cross Wires is not visible on the bright port-ion of the field.

y A practical embodiment of the invention is represented in the accompanying drawings forming a part of this specication, in

which similar characters of reference indi,-

.cate corresponding parts in all the views.

Figure 1 is a perspective view of a transit telescope, provided with the improved sight; Fig.' 2 is a longitudinal central section of the same; Fig. 3 vis a view of the field of observation with the target in the vcenter of the eld; Fig. 4 is a similar View of the same with the targets appearing at the .upper and lower portions of the field; and Fig. 5 is a similar view' of the same with the Itargets appearing at the sides of the field.

The Gaiilean telescope shown in Figs. 1 and 2 is provided with the usual tube A in which is mounted the objective B and the concave eye-piece C. A sightin wire D is associated with the eye-piece and the sighting wire :may be in th'e form of a single Wire extending diametrically of the eyepiece C, or in the form of cross Wires, the

sighting Wire'being secured in position by suitable attaching means E held on the tube A, the sight Wires'extending through slots in the tube of the eye-piece C in case the eye-piece is the movable part.

A diaphragm F is associated with the objective B, preferably by mounting such diaphragm in the outer end of the tube A and fastening the same by a screw G to a plug G', as indicated in Fig. 2. The diaphragm Fis provided with a central opening I4", which may be square, as shown in Fig. 1, and' the diaphragm is also provided with horizontal slots F2 and vertical slots F3 in alinement with the sighting Wires D. The slots F2. F3 preferably extend from the pcripheral edge of the diaphragm F to Within a short distance of the corresponding walls of the opening F, as plainly indicated in Fig. l, so that when the telescope is used for sighting purposes then the lield of observation H shown in Figs. 3, 4c and 5 discloses a central bright portion H due to the opening F and dimmer portions H2 due to the slots F2, F3, the dimmer portions H2 appearing half round with the centers at the inner ends of the slots F2, F3, that is,

in close proximity to the corresponding edges of the brighter central portions H.

It is well known that in a Galilean telescope as heretofore constructed cross Wires cannot be used for sighting purposes but by'providing a diaphragm with the slots F2, F3 the side portions of the cross wires D appear as black bands or stripes Dfli'n. v'

fullest advantage in the field H, and it is measuring a vertical angle. This is accomplis-hed by the observer moving the eye across the eye-piece C in a corresponding direction while the telescope is clamped in nositioin" In Fig. 3 the target I is shown with -its center iii line with both horizontal and vcrtical sight bands D', its center coinciding with the line of collimation. In order to make sure that the center of the target I is in the vertical sight plane the end of either one of the vertical sight bands D may be brought in contact With it as indicated in Fig. 4 by the observer moving the eye up or down in line With the vertical sight bands D. In this case the horizontal sight bands D disappear. In order to test the position relative to the horizontal sight plane the observer moves the eye along the horizontal sight bands D until the end of one of the horizontal sight bands is brought to the target I as shown in Fig. 5. In this case the vertical sight bands disappear. It

` will be noticed that by the peculiarity just described the accuracy of the sight compares favorably With that of the telescope sights now generally used.

When using the telescope on guns or rifles in taking aim, the target is brought in line with all the sight bands D', as shown in Fig. 3.

The diaphragm F is provided with a slot F* for the passage of the screw Gr so as to allow of properly adjusting the diaphragm F with a view to move the slots F2 and F3 in accurate register with the cross wires D. The slots F2 and F 3 terminate a distance from the walls of the opening F. so as to avoid glimmering in the field opposite the sight stripes or bands D.

It will be noticed that by the arrangement described the Galilean telescope, that is, one with a concave eye-piece, can be usedfor sighting purposes` and as such telescope is very short. it is well adapted for use on portable surveying instruments, ril'les and other devices. The telescope is short owing to the distance between the objective and the eye-piece being the difference between their focal length instead of their sinn as is the case in a telescope having a convex eye-piece. A concave eye-piece gives a brighter field because it absorbs less light on account of using but a single lens instead of a series of spaced lenses as is the casein terrestrial eyepieces. The field has less color and distortion because itis less affected by chromatic and spherical aberration and hence the telescope gives a better definition, which is an important factor in a surveying instrument or`in a gun sight.

The telescope sight shown and described is simple, cheap in construction and accurate, and is free from parallax. The sight is adjusted for distance Without interfering with the line of collimation. It is well known that in a common telescope the line of collimation is determinedby the cross iwires and the center of the objective, and

the latter is to be moved to adjust for distance, and to insure this adjustment Without disturbing the line of collimation, a costly construction is required.v Moreover, there is always parallax' unless the adjustment for distance is made with care. In the arrangement described, the line of vcollimation is determined by the cross wires and the slots of the diaphragm, and neither of these need be moved to adjust the telescope to different distances. The adjustment may be made by moving either the eye-piece or the objective, and there is no parallax even if an adjustment is not carefully made, or if it is not made at all, it being understood that the adjustment is left to be made by the eye, as l't generally is to some extent. A telescope of low power with a long and small tube such as are used for hunting gun sights, may be made with non-acromatic lenses thus providing the advantage owing to the fact that acromatic lenses are spoiled by dampness while the others are not.

Although the sighting wires D are shown and described as attached to the tube A and the' diaphragm F is illustrated and described in front of the objective B, such constructions may be varied Without departing fr om the spirit of my invention, which consists essentially in providing a Galilean telescope with a sighting device, the cross wlres of which are associated with the concave eyepiece and the diaphragm is associated with the objective either in the front or the rear thereof. 5

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1;A` Galilean telescope provided. with a sight attachment comprising a sighting wire and a diaphragm, the sighting Wire being associated with the concave eye-piece of the telescope and the diaphragm being associated with the objective of the telescope, the diaphragm having an opening and slots and the said sighting wire being in alinement withv the said slots.

2. A Galilean telescope provided with a sight attachment comprising a sighting Wire and a diaphragm, the sighting wire being wire being in alineinent with the said slots.l

associated with the concave eye-piece of the In testimony whereof I have signed my 10 telescope, and the diaphragm being associname to this specification in the presence o f ated with the objective of the telescope, the two subscribing Witnesses.

diaphragm havin an opening and horizonl WILLIAM V. HUKILL;

tal and Vertical s ots, the inneriend ofveach Witnesses:

A. L. PILCHARD,

slot terminating a-distance 'from the Wall Mrs. R. L. TINSLEY.

of the said opening and the saidsighting 

